Augmented reality (AR) is a technique for recognizing a reference object (marker) included in an imaged image and adding prescribed information to the recognized marker and displaying. AR involves first an object being photographed using a camera and then the photographed image data is input into an AR application which carries out processing related to AR. The AR application recognizes the marker included in the input image data and adds and displays prescribed information corresponding to the recognized marker.
The camera has an auto-focus function for automatically bringing the object into focus. The camera's photographing timing is a fixed frame interval. The AR application does not control the actions of the camera, and the photographing and auto-focus actions of the camera are independent of the AR application.
The following first and second techniques represent photography and photographic image processing.
An imaging device of the first technique is provided with an imaging unit, a focusing unit, and an object searching unit. The imaging unit converts an optical image formed on an image forming surface into image data. The focusing unit moves a focus lens for performing focus adjustment of the optical image to detect a focus position, and positions the focus lens at the detected focus position. The object searching unit searches a prescribed search region in the current video signal region to determine whether an image region of the object in a video signal region brought into focus with the most recent focusing action changes in relation to a prescribed threshold, and reactivates the focusing unit only if the object image region has changed. This technique is disclosed for example in Japanese Laid-open Patent Publication No. 2007-52061.
The second technique involves a microcomputer for focus control stopping a focus adjustment after bringing an object into focus. A determination is made thereafter as to whether the focusing is attained for a plurality of blocks that constitute the photographed image. While performing pan/tilt driving, a focus adjustment of a focus adjusting unit is activated when all the blocks that are in focus deviate from the photographed image, or when only a prescribed number remain, or when a prescribed ratio of the blocks is deviated. This technique is disclosed for example in Japanese Laid-open Patent Publication No. 2007-52349.